The food and beverage industry presently uses a wide variety of containers in packaging a vast assortment of materials and combination of materials, e.g., paperboard, glass, metals such as aluminum, and various plastics. Of course, there are advantages and disadvantages associated with each material. For example, paperboard is a relatively strong and inexpensive container material, but unfortunately is quite permeable to gases such as oxygen. Therefore, foods and beverages stored in paperboard containers tend to lose their freshness and degrade over a short period of time. In comparison, containers made from glass, metals, and some plastics are relatively impermeable to gases, but are rather expensive due to the high cost of those materials.
In recent years, the food and beverage industry has turned to bag-in-box (BIB) composite containers to package such products as bulk milk and wine. These BIB containers, which basically consist of a plastic inner bag within a sturdy outer paperboard box, combine the low cost strength of paperboard with the protection offered by various plastics. However, in automatically constructing, filling, and sealing most BIB containers, relatively complex and slow machinery and methods are typically used, which handicap the BIB material cost savings advantage. Furthermore, many prior art BIB container making apparatus and methods produce leaky and gas permeable containers.
One prior art bag-in-box and method of making the same is disclosed in U.S. Pat. Nos. 4,386,923; 4,484,431; and 4,484,431; which issued to Okushita and being incorporated herein by reference. Briefly, Ikushita's method beings by placing an unfilled bag, which comprises two substantially rectangular, superposed layers of flexible material sealed together along their distal edges, within an outer box. Next, the bag is inflated within the box, followed by placing the desired product into the bag through an attached fitment that projects outwardly from the box. Although the economics of such a method and apparatus are not known, it is known that a relatively high percentage of the inner bags made in this manner tend to leak due to the difficulty in consistently obtaining reliable heat seals along the bag's distal edges and between the bag/fitment interface.
Another prior art method of making a bag-in-box container is disclosed in U.S. Pat. Nos. 4,358,918 and 4,524,564, both issued to Grooms et al. and being incorporated herein by reference. Grooms' disclosed method begins by erecting an outer paperboard carton, followed by vacuum drawing a heat-sealed bag containing product within the erected outer carton. Unfortunately, as with Okushita's BIB container and method, Grooms' BIB method and apparatus produce a high percentage of leaky containers. In addition, since the disclosed BIB container is specifically intended for packaging discrete articles where reclosability is not critical, the container does not appear to be suitable for packaging a pourable liquid product that requires a pour spout, preferably one that is reclosable.
In providing a BIB composite container with a pouring spout, most prior art methods have relied on heat-sealing an annular flange of a pouring spout to the bag. Examples of this technique are shown in U.S. Pat. Nos. 3,363,807; 4,214,675; 4,322,018; and 4,355,737. However, as with heat-sealing the distal edges of a bag, it is rather difficult to consistently obtain reliable, non-leaking heat seals between the bag and spout.
Another problem associated with prior art BIB containers is obtaining a reliable interlock between the inner bag and the outer carton, which is particularly important in the case of a BIB having a pouring spout that is adapted to receive a screw cap or other closure means. Most prior art manufacturing methods require an additional step to achieve an interlock, such as gluing the bag to the inside of the box as disclosed in the Okushita references, or an added structural interlock device such as those disclosed in U.S. Pat. No. 4,524,883, which issued to Herring, and U.S. Pat. No. 4,174,051, which issued to Edwards et al. As expected, such additional steps or devices add significant costs in making BIB composite containers.
In light of the above, a principal object of the present invention is to provide a bag-in-box composite containers that is sturdy, relatively impermeable to gases, non-leaking, and inexpensive to make.
Another principal object of the present invention is to provide a BIB composite container wherein the inner bag and the inner bag/pouring spout interface have no heat seals or other discontinuities.
Another object of the present invention is to provide an inexpensive and reliable way of interlocking a BIB's pouring spout to the outer carton.
Another object of the present invention is to provide a convenient means for a consumer to grasp a BIB container for easier pouring of the product contained therein, as well as a means to view the product.
It is another object of the present invention to provide an economical manufacturing method of making bag-in-box composite containers.
Another object of the present inention is to provide efficient apparatus for making bag-in-box composite containers.